1. Field of the Invention
This invention pertains generally to vessels similar to mash vessels and cereal cookers and more specifically to a mixer shaft sealing system for vessels having a bottom entry mixer shaft.
2. Description of the Prior Art
Brewery vessels having bottom entry drive seals are notoriously plagued by problems directly attributable to the drive seals. The conventional seal usually consists of a stuffing box, a gland follower and packing with seals. Water is injected between the shaft and packing and seal to keep the shaft clear of abrasive grit material.
However, due to wear and the vertical and dynamic movement of the brewery vessel during the normal course of the brewing function, the product content from the vessel, for example either the mash in a mash vessel, or the cereal in a cereal cooker will escape from the vessel along the mixer shaft and through the drive seal.
Any leakage of that kind results in leakage into the gear box containing the drive train with all of the consequences of high maintenance costs and down time should such elements need special attention.
The inability of the drive seal to accommodate axial and radial movements also subjects the mixer shaft to high torque loading, thereby causing high amperage requirements on the drive motor whereupon the drive motors will often cut out on overload.
Product leakage along the seals will also cause scoring of the packing and the shaft due to the abrasiveness of the product contents of the brewing vessel.
As a result of the foregoing, high energy costs are incurred and unacceptable unsanitary conditions are produced in the brewing environment.